Anyone passing Liu Xiaobo's apartment complex as they made their home from work on Friday evening would have witnessed an unusual scene.

As the Nobel Peace Prize ceremony was taking place in Oslo, a group of foreign journalists gathered on the street outside the compound that houses the prize winner's Beijing home.

They were prevented from entering by police manning a barrier. Other security officials - some in uniform, some not - mooched around nearby.

Why China considers Liu Xiaobo a threat

1989: leading activist in Tiananmen Square protests for democratisation; jailed for two years

1996: spoke out against China's one-party system; sent to labour camp for three years

2008: co-author of Charter 08, calling for a new constitution, an independent judiciary and freedom of expression

2009: jailed for subversion for 11 years; verdict says he "had the goal of subverting our country's people's democratic dictatorship and socialist system. The effects were malign and he is a major criminal".